The airbox to the PVP carburetor, have on filter inside,
and there is a 5 mm. hole in the bottom, so the the water can come
out if you drive wet races. The size of the box inside is 150x500 mm. The
part number of the airbox is 4032.

This is the filter inside the airbox, the filter
have part number 4033

Inside the airbox is there this fiber ring as you can
see on the photo, to give the perfect bellmouth.